Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

- Add Intel firmwares for Intel PRO/Wireless LAN 2100/2200/2915 cards in a
uuencoded format along with their respective LICENSE files.
- Add new share/doc/legal directory to BSD.usr.dist mtree file. This is the
place we install LICENSE files for restricted firmwares.
- Teach firmware(9) and kmod.mk about licensed firmwares. Restricted firmwares
won't load properly unless legal.<name>.license_ack is set to 1, either
via kenv(1) or /boot/loader.conf.

Reviewed by: mlaier, sam
Permitted by: Intel (via Andrew Wilson)
MFC after: 1 month